The Mets are looking for a corner outfielder with power, and want to trade card-playing devotee Rickey Henderson in order to clear the way for one. A major league source outside the Mets told The Post that during the playoffs the Mets were telling people they were looking for someone with thump to replace Henderson in left field.

Two Mets sources have confirmed that the Mets are prepared to trade Henderson, but are not necessarily committed to trading for anything, as they would gladly do with Bobby Bonilla. Although Henderson had a good overall season here, they have basically reached their limit with him.

“You don’t know when he’s going to play hard for you,” a front office source said. “I think a lot of people saw that on TV.”

According to people privy to the Mets’ still-formulating offseason plans, no players have yet been targeted for them to either trade for or sign, not even Greg Vaughn. The Reds leftfielder has filed for free agency, but his name has not yet been mentioned in team meetings.

Every move they make at this point hinges on whether or not they sign John Olerud.

Overall, Henderson had a great statistical year for the Mets, hitting .314, which was his highest average since his MVP season of 1990 with the Athletics. He stole 37 bases, knocked in 41 runs, walked 82 times and had a .423 on-base percentage, the seventh-highest in the National League. He is also credited with developing Roger Cedeno into a major base-stealing threat.

But there was a downside to Henderson’s contributions as well, including brutal defense much of the time, and significant base-running lapses, particularly at the end of the season.

Then, of course, there was his infamous card game with Bonilla during the end of Game 6 of the NLCS, and his public confrontation with Bobby Valentine and Turk Wendell after he was taken out of Game 4 for a defensive replacement after he had already taken the field.

Vaughn earned a $5,615,428 base salary last year and is expected to try and squeeze $50 million for five years out of some team. He hit 45 home runs in ’99, tied with Chipper Jones for third-most in the NL, but he also struck out 137 times and as one agent put it, if he couldn’t get along with Padres GM Kevin Towers, teams will be wary of an attitude problem.

Another leftfielder available for a major trade would be Juan Gonzalez, whom the Rangers would trade for top pitching prospects before he gets his huge free-agent payday in 2001.